Synthesis gas generation



Oct. 13, 1953 F. H. MOORE SYNTHESIS GAS GENERATION Filed March 2. 1948INVENTOR.

FREZEIP/c/. a RE Patented Oct. 13, 1953 UNITED: sures PATENT OFFICE;

SYNTHESIS GAS GENERATION;`

FrederiwE More, Long Beach; Califl, asigio' to The' Texas' Company, NewYork, N.:1 a com -z;

po'ation of Delaware Application March 2, 1948, SerialLN 0112555 ;4

(Cl. '48--206J 2 Claims.

This invention rela tes to *a process and apparatus for, the generationof gases comprisng` carbon monoxide from ;carbonaceous materials. Inone-of its more specific-*aspects it 'relates'to a process and apparatusfor the generationor a generation of a mixture of carbonmonoxide and`hydrogen. I`he -invention is particularly suited to the productionof afeed gas 'for 'the synthesis of hydrocarbons. Various solid carbonaeeousfuels may be used; e. g coal, ligniteyand the like.

' An object of --this invention-is to provide a i process---for thegeneration ofcarbon -monoxide and --hydrogen from-carbonaceousmaterials.

Another object is to provide-a process particularly suited tothe-generation of a feed gas -for thesynthess of hydrocarbons fromcoal.-`

A furtherobjectof this invention is to provide apparatus for' thegeneration of carbon monoxide and hydrogen from carbonaceous materials.

Gasification of powdered coal by partial combustion incylindricalgenerators 'has been proposed heretofore. To 'the `best of myknowledge, however,` these-have not been commercially successful.'Reactors of this sort Were tried in Germany but Were not developedbeyond theexperimental stage. Man problemsremained unsolved when, theWork was abandoned. Difiiculties particularly were experienced inobtaining substantially complete reaction of carbon and in preventingundesirable slag accumulaton due to fuson of the ash.. Themethodand:apparatusof my invention provides; a; highrateof carbonreaction, resulting in eflicient` carbon utilization. Handling of slag`is accomplished withoutparticular dfficulty due to the improved `methodand apparatus by which the -slag ismaintained in mol-ten condition.

In the gasification of carbonaceous material with oxygen, particularlysolid fuels, thereaction 'between the oxygen and fuel results in the'prov 2 duction of carboi'` diokide according?. to the equationc* Theoxidaton reaction, being highly exothermic. releaseslarge quantities ofheat. l v

Thecarbon `dioxide,. so produced, in contact with `hotcarbon, in turn,reacts with the carbon to produce ca'bon monoxide;`

steam also reacts with heated carbon-to produce carbon monoxide andhydrogenz" These reactions are' endothermic' and require heatfromanother source; c I Heat for the endothermc reactions maybe"supplied from the exothermic reaction. 4 Thus,-in a gas generatorthereshould be a free transfer of 'hoat between-the zone in which carbondioxide is formedand* the'zone in which -carbon` dioxide s consumed byreaction with c'arbon. i

The water gas Shift reactionz* also takes: place in the generatorl 'The'water' gas shift reactionhas little infiuence on the 'thermal balancein the generator. 'At high temperatures, above about 1500 F., theproducts on "the left handside of the'equationa tendto predominate asgoverned by -thevvell known laws of chemical equilibria whereas theconverse is true 'at low temperaturesun The 'quantity of hydrogenin .theproduct gas may be controlledby controlof conditionsafiectingsthewater'gas :Shift reaction. Thus hydrogen may be generatedat the lexpense of carbon monoxide *in a shift converter, `as .is

knownrin the art; or the. reaction efiluent from'the generator maybequenched .to substantially prevent the water.. gas shift reaction .oncooling of the eflluent.

The presentinuention will be 'described for the sake of Simplicity, withreference to coal as a fuel.. -It will be lnnderstooduthat 'coalris usedas .a. specific example: and r; that a the' apparatus' ;and

method. described ais notxnecessarily limited to the usezof coal; l

In `accordance 'with *this invention coa 'is crushed and charged intothe reaction zone'in suspension in steam. -Oxygen is introduced into thereactor -separately and-brought into'intimate contact `with'theparticles of coal.` P-eferably the oxygen-containing gas 'has' an oxygenconcentratiomofg per cent b'y Volume or greater 'and' is 'preheatedprior' to 'introduction' into the are fed into the generator in a novelmanner, as

is described in detail hereinafter, which permits operation at hightemperature while at the same time protecting the walls of the reactorfrom excessive localized overheating.

The exothermic reaction or burning which takes place upon contactbetween the coal and oxygen releases heat which is utilized in a veryeffective and efficient manner in this invention to supply'heat forensuing endothermic reactions. Gases comprising carbon monoxide, carbondioxide and hydrogen result from the oxdation of the carbon in thepresence of steam. The steam and carbon dioxide react with the highlyheated carbon in the coal to produce the desired carbon monoxide andhydrogen.

Due to the novel manner in which reactants are ied into and gaseousproducts are withdrawn from the reaction zone, efiicient heat transferand eective reaction conditions are obtained. This eflicient heattransfer is also thought to be enhanced by effective mixing andunimpeded radiation from exothermic to endothermic points of reaction.

Elevated temperature and pressure are beneficial to the desiredreactions in the overall process. Temperatures within the range of 2000-4000 F. are desirable; the temperature is limited by the availablematerials of Construction. Temperatures as high as materials ofConstruction will per'nit are desirable to give high reaction rates,;particularly in the case of the endothermic reactions. Elevatedpressure increases the concentrations of the gaseous reactants.Preferably, a pressure in excess of 100 pounds per square inch gauge isused.

The apparatus describedtherein and forming a part of my inventionprovides for carrying out the reaction ina most eflicient manner as willbe more fully brought out in the following detailed description withreference to the accompanying drawings.

Fig. 1 is a vertical cross-sectional View of a preferred embodiment ofapparatus forming a part of my invention.

Fig. 2 is a horizontal cross-sectional View taken along the plane 2-2 ofFig. 1.

The generator illustrated in the drawings is particularly suited for thegasification of powdered coal for the generation of synthesis gas. Forthe purpose of facilitating the detailed description of the apparatusillustrated, the deseripticn will be made throughout with reference topowdered coal. Other solid carbonaceous materials may be used, forexample, coke, lignite, and the like.

With reference to the drawings, the generator is provided With an outercylindrical steel shell 5 capable of Withstanding the Operating pressureand a refractory lining 6 of a material suited to the temperatureconditions encountered in operation. Crushed coal in admixture withsuper-heated steam is introduced into the upper end of the elongated,cylindrical, vertical reaction zone 'I through a port 8. Oxygen isintroduced into the reaction zone throu h a port 9 V which dischargesthe oxygen stream directly into .the stream of coal and steam. Both thestream of coal and steam and the stream of oxygen are introduced intothe upper end of the reaction zone at its periphery and substantiallytangent thereto. By this arrangement the coal and oxygen are intimatelyadmixed within the reaction zone, and the stream of oxygen is preventedfrom directly impinging on the wall of the reactor. The reactor wall isprotected from the oxygen introducedthrough port 9 by the stream of coaland steam introduced through port 8.

The oxygen and coal react immediately with the liberation of largequantities of heat. The gases and heated carbon particles resulting fromthe oxidation reaction are carried downwardly in-reaction zone 'Iadjacent its periphery or the inner wall of the vessel. The tangentialintroduction of the reactants imparts a swirling motion to the gasstream and the particles of heated carbon. .Carbon dioxide in the hotgas stream reacts with the heated carbon particles in the lower portionof the zone to produce carbon monoxide.

Molten ash and slag thrown out of the gas stream by the whirling motionof the gases are collected at the lower end of the reaction zone fromwhence they are discharged through slag tap !0 into the exit conduit ll.The slag disposal piping !2 is lined with a refractory material !3.

Product gases comprising carbon monoxide and. hydrogen are Withdrawnfrom a point along the axis of the reaction zone below the point ofintroduction of reactants. The synthesis gas so produced is withdrawnfrom the reaction zone through a chimney M. which extends into thereaction zone to a point slightly above its center. The synthesis asesare discharged through the outlet duet [5 into the discharge line ITwhich is provided with a refractory lining !8. The synthesis gas may bequenched as by contact with a spray of Water and further cooled bypassage through a waste heat boiler for the generation of steam.

A pilot burner 2l extends through an opening in the upper portion of thevessel above the point at which the oxygen and the coal meet. Fuel gasis supplied to the burner through line 22 and oxygen through line 23.

Any entrained particles of molten ash discharged With the synthesis gasare converted on cooling to small solid particles in the form of fly ashwhich can be readily removed from the synthesis gas.

In the operation of the generator, crushed coal having a particle sizeof about %E inch in diam eter is injected into the generator throughport 8 by suspension in a stream of super-heated steam at a pressuresufficient to cause flow through port 8 at a relatively high velocity.Oxyeh under pressure is fed into the generator through'port 9 at avelocity suficient to insure mixing with the coal. Particles of coalare'car- 'ried in the gas streams around the periphery of heater issuitable for heating steam to temperatures above 1000 F.

In the description of the apparatus, the coal and steam enter one of theports and oxygen enters the other. While this particular arrangement isvery satisfactory and probably generally preferred, it is not essentialto successful operation. A gas other than steam may be used forpropelling the coal into the generator. A hydrocarbon gas, for example,is suitable either alone or in admixture with steam. Theoxygencontaining gas may also be used subject to the problems andlimitations imposed by preoxidation of the coal particles which issometimes desirable to prevent agglomeration. steam may, of course, beadmixed with'the oxygen admitted through either port. Regardless of thecombination of entering reactants, it is desirable to introduce thereactants tangentially and' to include steam, oxygen, and solid carbonin the feed streams. The particular apparatus and novel method of thisinvention ofier advantages of Simplicity, while retaining efi'iciency ofoperation not realized by any systems of the prior art of which I amaware.

In the interests of Simplicity of illustration and description,auxiliary equipment not; necessary to the description of the generatorhas been omitted. Details of the quench of the synthesis gas anddisposal of slag have been omitted since they are not essential to theinvention. The synthesis gas may be quenched by direct contact with a,spray or Water. Partlcles of entrained ash or slag may be separated inconventiona manner, e. g., by means of a cyclone type Separator. Theslag is conveniently disposed of by discharging it into water in aseparate vessel maintained at the same pressure as the generator. Otherforms of apparatus may be used for carrying out the process of thisinvention.

Obvously many modiflcations and variations of the invention ashereinabove set forth may be made without departing from the spirit andscope thereof and therefore only such limitations should be imposed asare indicated in the appended claims.

I claim:

1. In a process for the production of a gaseous mixture comprisinghydrogen and carbon monoxide from a solid carbonaceous fuel by reactionwith steam and oxygen, the improvement which comprises introducing astream of solid carbonaceous fuel Suspended in steam into an elongatedvertical cylindrical reaction zone at a, point adjacent the upper endthereof and in a direction substantially tangent to the periphery ofsaid zone, introducing a stream of oxygen-contrainng gas free from fuelinto said zone at a point adjacent and upstream of said point ofintroduction of said stream of steam. and solid fuel into confiuencewith said stream of steam and particulate carbonaceous material wherebythe reactants and resulting product gases are given a spiral motiondownwardly along the wall of the reaction zone, and withdraw'ng all ofthe gaseous product comprising carbon monoxide and hydrogen axiallythrough the upper portion of the reaction zone from a point within saidzone along the axis thereof below the point of introduction of saidreactants and above the center of said zone, all of the reactants beingintroduced into said zone above the level of said point of withdrawal,whereby the reactants and resulting reaction products form a streamflowing spirally downwardly in an annulus from the upper portion of thereaction zone to the lower portion of said zone and thence upward alongthe axis thereof to said point of withdrawal in direct radiant heattransfer relation with said downwardly fiowing spiral.

2. A process as deflned in claim 1 wherein said oxygen-containing gascontains in excess of Volume per cent oxygen.

FREDERIC H. MOORE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,833,964 Cross Dec. 1, 1931 1,924,856 Heller Aug. 29, 19332,028,946 Niconofi Jan. 28, 1936 2,302,156 Totzek Nov. 17, 1942 2388348Stimson Nov. 6, 1945

1. IN A PROCESS FOR THE PRODUCTION OF A GASEOUS MIXTURE COMPRISINGHYDROGEN AND CARBON MONOXIDE FROM A SOLID CARBONACEOUS FUEL BY REACTIONWITH STEAM AND OXYGEN, THE IMPROVEMENT WHICH COMPRISES INTRODUCING ASTREAM OF SOLID CARBONACEOUS FUEL SUSPENDED IN STEAM INTO AN ELONGATEDVERTICAL CYLINDRICAL REACTION ZONE AT A POINT ADJACENT THE UPPER ENDTHEREOF AND IN A DIRECTION SUBSTANTIALLY TANGENT TO THE PERIPHERY OFSAID ZONE, INTRODUCING A STREAM OF OXYGEN-CONTRAINING GAS FREE FROM FUELINTO SAID ZONE AT A POINT ADJACENT AND UPSTREAM OF SAID POINT OFINTRODUCTION OF SAID STREAM OF STEAM AND SOLID FUEL INTO CONFLUENCE WITHSAID STREAM OF STEAM AND PARTICULATE CARBONACEOUS MATERIAL WHEREBY THEREACTANTS AND RESULTING PRODUCT GAS ARE GIVEN A SPIRAL MOTION DOWNWARDLYALONG THE WALL OF THE REACTION ZONE, AND WITHDRAWING ALL OF THE GASEOUSPRODUCT COMPRISING CARBON MONOXIDE AND HYDROGEN AXIALLY THROUGH THEUPPER PORTION OF THE REACTION ZONE FROM A POINT WITHIN SAID ZONE ALONGTHE AXIS THEREOF BELOW THE POINT OF INTRODUCTION OF SAID REACTANTS NDABOVE THE CENTER OF SAID ZONE, ALL OF THE REACTANTS BEING INTRODUCEDINTO SAID ZONE ABOVE THE LEVEL OF SAID POINT OF WITHDRAWAL, WHEREBY THEREACTANTS AND RESULTING REACTION PRODUCTS FROM A STREAM FLOWING SPIRALLYDOWNWARDLY IN AN ANNULUS FROM THE UPPER PORTION OF THE REACTION ZONE TOTHE LOWER PORTION OF SAID ZONE AND THENCE UPWARD ALONG THE AXIS THERREOFTO SAID POINT OF WITHDRAWAL IN DIRECT RADIANT HEAT TRANSFER RELATIONWITH SAID DOWNWARDLY FLOWING SPIRAL.